This invention relates generally to x-ray diagnostic medical imaging and more particularly, to methods and apparatus for x-ray image detector assemblies.
In many x-ray imaging system configurations, an x-ray source projects an area beam which is collimated to pass through a region of interest of the object being imaged, such as a patient. The beam, after being attenuated by the object, impinges upon an array of radiation detectors. The intensity of the radiation beam received at the detector array is dependent upon the attenuation of the x-ray beam by the object. Each detector element, or pixel, of the array produces a separate electrical signal that is a measurement of the beam attenuation at that location of the detector. The attenuation measurements from all the detector pixels are acquired separately to produce a transmission profile.
Digital X-Ray image detectors are either fabricated on a monolithic substrate, such as glass or crystaline silicon, or on multiple substrates, which must then be integrated into a single image detector. One limitation is that crystalline silicon (Si), whether single crystal silicon (X—Si) or polycrystalline silicon (P—Si), is only available to be processed in wafer sizes that are significantly smaller than the desired sizes of X-ray image detectors for some medical applications. This limitation has led to the development of X-ray image tiled detector assemblies. However, the interconnection of multiple substrates into a single image detector presents challenges for achieving low-to-zero defect connections on large arrays, and also presents challenges in avoiding image defects at the interior edges of the arrays, where two substrates are adjacent and share a seam.